Adhesive composition



United. States Patent ADHESIVE COMPOSITION James H. Groves, Lombard, 111., assignor to American fan Company, New York, N.Y., a corporation of New ersey N0 Drawing. Filed June 28, 1955, Ser. No. 518,671 6 Claims. (Cl. 260-42) The present invention relates to an adhesive-composition comprising a polyamide resin. More particularly it relates to a high strength, quick setting adhesive composition comprising the reaction product of a linear polyamide and an epoxy resin.

Because of their high chemical inertness and high tensile strength, linear polyamide resins are very desirable as organic adhesives for the cementing of various surfaces together, principally metals. However, a deficiency common to all of these polyamides is their poor adhesion to .most if notall metal surfaces. Applicant has succeeded in overcoming such deficiency after. considerable experimental work.

It is therefore an object of the present invention to provide a novel adhesive composition comprising a linear polyamide.

Another object is to provide a polyamide adhesive composition having high strength in adhesion as well as cohesion.

A further object is to provide a polyamide adhesive composition which may be used to effect high strength bonds in a very short interval of time.

An additional object is the provision of a polyamide adhesive composition which adheres to a great variety of surfaces.

Still another object is to provide a polyamide adhesive composition which is an effective substitute for solder as a bonding agent in the side seam of a sheet metal container and has substantially the same or greater bond strength as metallic solder.

Numerous other objects'and advantages of the invention will be apparent as it is better understood from the following description which is of a preferred embodiment thereof.

' Applicant has discovered that the stated objects can be obtained by combining with a linear polyamide an epoxy resin as an adhesion promotor for the polyamide. When this composition of linear polyamide and epoxy resin is heated in contact with the surfaces to be joined, to a temperature above the melting point of the polyamide, and held at this temperature for a brief interval of time and thereafter cooled, upon setting and hardening of, the 1 cement or adhesive there results between the surfaces a V 2,962,468 Patented Nov. 29, 1960 high strength bond comparable to or greater than that of metallic solder. Unexpectedly applicant found that this increased adhesion of the linear polyamide to the substrate is not restricted to anyone single material or metal but that the combination of the epoxy resin with the linear polyamide increased the adhesion of the polyamide to a great variety of metallic and non-metallic surfaces.

The polyamide resins useful in the present invention may difier considerably in method of preparation and starting materials. However common to all of these resins is the presence of a plurality of recurring groups having the structure:

separated by alkylene groups containing at least 2 carbon atoms, and where R is hydrogen, a lower alkyl group having 1, to 4 carbon atoms, or an alkoxy group having 1' to 4 carbon atoms and having an intrinsicviscosity of at least 0.4. Intrinsic viscosity is defined in U. S. Patent 2,130,948 to W. H. Carothers. Polyamides in which R is hydrogen'are preferred.

Among the polyamides which are useful in the present invention are polypentamethylene sebacamide, polyhexamethylene adipamide, polyhexamethylene sebacamide, polydecamethylene adipamide, polydecamethylene sebacamide, poly-m-phenylene sebacamide, o-amino-caproic acid polymers, 7-arnino-heptanoic acid polymers, 11- amino-undecanoic acid polymers, l2-amino-stearic acid polymers, as well as otherpolyamides and interpolyamides of the type mentioned in U.S. Patents 2,071,253, 2,130,523. and 2,130,948, issued to W. H. Carothers, and U.S. Patent 2,285,009, issued to M. M. Brubaker et al.

The epoxy resin adhesion promotors. for the polyamides belong to a class of complex, polymeric epoxy-hydroxy ethers resulting from the catalyzed reaction of a polyhydric alcohol, e.g. glycols, glycerine, trimethylol propane, polyhydric phenols, polyphenols, with an excess of an epoxide, e.g. epihalohydrins, alkylene oxides, as described in U. S. Patents 2,456,408 and 2,592,560, issued to S. O. Greenlee. The principal'product of this reaction is a resinous epoxy glyceryl polyether comprising epoxy glyceryl radicals, hydroxyl or chloride substituted glyceryl radicals, and the divalent residue of the polyhydric alcoand promoter are brought together in a more or less 2,962,468 V 3 4 instant invention may be represented by the following EXAMPLE III Structural formulas: The plasticized ll-amino-undecanoic acid polymer of Polyether A Example I was immersed in a 20% solution of 21 Polyr 1" H2O-CHCH OCHrCHCHqO-CHz-CHCH O-CH -G CHA which is the reaction product of glycerine and an epoxide ether B having an epoxide equivalent of 190 to 210 in such as epichlorohydrin and has an epoxide equivalent butanol-toluene and immediately removed. The film of from 140 to 165; and was then allowed to drain and dried for subsequent use. To each of two black iron sheets, a layer of the treated Polyether B film was applied. Each sheet with its resin layer was I HzC CHCHz-O-RO-CHz-CHCHg-O R-OCHr-CH-CH2 where n is zero or a positive number (whole or fracheated to 470 F. and held at this temperature for sectional) less than 2 and R is the hydrocarbon radical of onds to permit the resin layer to melt and wet the metal p,p-dihydroxy diphenyl dimethyl methane (bisphenolsurface. The two sheets were then pressed together with A). Polyether B is the reaction product of bisphenol-A the resin adhesive disposed in between and the assembly and an epoxide such as epichlorohydrin and has an was held in this position for another 60 seconds and at a epoxide equivalent of about from 175 to 375 and an avertemperature of 425 F maintaining a glue line thickness age molecular weight of about from 380 to 750. of 2 to 3 mils. Thereafter the assembly was chilled to It is believed that the outstanding adhesive properties set the cement. of the polyamide-epoxy resin combination are due to a EXAMPLE IV reaction between epoxide groups and reactive hydrogen m pninanly N'hydrogen.atoms m the f i cept that a solution of a Polyether B having an Thls reaction takes place polyaimde 1s m epoxide equivalent of 190 to 210 in butanol-toluene was when State However pnor to thls reactlon the resm substituted for the 10% solution of the Polyether A and a holding time of 30 seconds was used after bringing together the metal sheets carrying the molten adhesive.

The method set forth in Example I was repeated exphysical combination. This physical combination may 3 be accomplished in any suitable manner, for example: by

treating a solid form of the polyamide, e.g. film, filament EXAMPLE V or rod, with a liquid promoter or a solution thereof in The Steps f Example I were repeated substituting an a Volatile solvent; or a film of P Y resm may be interpolyamide formed by the interpolymerization of (by posited on the surface that is to be bonded and the p01Y- 33 .weight) hexamethylenediammonium adipate, 15% amide thereafter applied to the thus coated Surfeeeof hexamethylenediammonium salts of oleic acid oxidation these methods, the one whereby a Solid form P the P acids and 6-amino-caproic acid as described in US. amide is treated with a solution of epoxy resin promoter Patent 2,235,009 for the 11 amino undecanoic acid poly. is p met and a 30% solution of the Polyether A for the 10% The fflllowing examples are by Way of Illustration only 40 solution. Also the holding time after joining the molten and are not to be considered as limitations upon the scope adhesive carrying surfaces was 60 Seconds of the invention. EXAMPLE I EXAMPLE VI Exam le V was re eated using a olyamide formed by Pre-formedfilm of plastlclzed-ll-aqnnomndecanolc 45 01 meri zin chemic all e uivalent amounts of pentaactd condensation polymer described in US. Patent y y 2 071253 about 3 to 6 mils to 006 inch thick methylene diamme and ethyl sebacate as described m was immersed in about a 10% solution of the Polyether T Q; 1 3 2 9 ifi; gg ig l gggigg izgg A in butanol-toluene and removed immediately. After of g g i i mg removal from the solution, the excess solutlon was al- The Same p'rocedure Set forth in Example I except for lowed to dram off and any residual solvent was evaporatsome variation in the time temperature y was :3 2; 12; 5: 1? $333 f i z s ggi gg eevab cessfully employed to bond metals having surfaces of A lager of thepcoated film of appropriate s'ize was nickel, zinc, tin, brass, aluminum, copper, various organic g 5 are; assessment tightest 51?; seetstee, eate toaout 0 .an e attistemperature for about 10 seconds after the film melted. The g}; ggi gg g z ig f {12 1 32 ggi z ggi two sheets were then pressed together cement sides fac- A g z gi 3 etger B havglg an mg each other, and held for an additional 15 seconds at epoxide equivalent of from 300 to was p y 500 temperature Whlle mamtammg a cemmt However it is to be understood that the epoxy resin adthlckness of two or three mils between the metal sheets.

hesion promoters may be used interchangeably with any ifi g f sheets were then rapldly chilled to Set the surface and with any of the polyamides defined hereinbefore. The polyamlde thls exampie contams as plastlclzers The amount of epoxy resin promoter needed to combenzomonobuqflamlde i a mlxture of and p 9 1 6 bine with the polyamide for the purpose of the instant inethyl sulfonamldes. Elther or both of these plasticizers Vention is relatively Small compared to the amount of may be omitted or other well known plasticizers may be polyamide' Weight ratios in the range of from about subsmuted therefer- 0.025 to 0.30 part of promoter per part of polyamides EXAMPLE II are operable. If the polyamide is in the form of a solid article, film, rod, etc., an amount of promoter is used The method set forth in Example I was followed exequal to about f 2D to 121) mgs. f promoter per cept that a 30% solution of a Polyether B having an Square inch f p01yamide epoxide equivalent of 185 to 200 was substituted for 10% Th following ble compares the peel strength, i.e. the

solution of the Polyether A and the holding time for the force required to separate two sheets bonded together assembled sheets was 30 seconds. by pulling an edge of one sheet in one direction and the opposed edge of the other sheet in an opposite direction over Canco roll guides at a speed of one inch per minute, of various materials bonded with an epoxy resin treated polyamide of the present invention to the peel heptanoic acid, a polymer of ll-amino-undecanoic, a polymer of IZ-aminostearic acid, and interpolymers thereof, said adhesion promoter being a resinous epoxy glyceryl polyether having terminal epoxy glyceryl radicals united strength of the same material bonded by the same meth- 5 with the divalent residue of a polyhydric alcohol through od but in which the linear polyamide is free from any ether oxygen atoms and having an epoxide equivalent epoxy resin adhesion promoter. By comparison, the peel of about from 140 to 375.

strength of a 30% tin-70% lead solder bond is 55 lbs. 2. The adhesive of claim 1 in which the polyamide is per .75 in. an ll-amino-undecanoic acid polymer.

Peel Strength in lbs. per Polyamide .75 in. Surfaces Bonded Promoter descrlbedln Example- Untreated Treated black iron Polyether A I v 18 101 tin plate T 12 87 Zinc plate. I 18 68 aluminum d0 T 9 61 copper. do I 4 43 brass rin T 9 42 nickel plate Ptggetalgr B-epoxide equivalent of from I 15 77 ohromatized steel Pozlyggger B-epoxide equivalent from 225 I 12 49 phenolic on metal -fdo T 16 79 oleoresin on metal Polyether T 56 black iron ,dn V 30 91 Do do v1. 97 glass 1 dn I 1,451 psi. 3, 315 psi. wood 1 do I 800 p.s.i. 2, 117 p.s.i.

1 Laps tested in shear instead of peel.

It is thought that the invention and many of its at- 3. The laminating adhesive set forth in claim 1 in tendant advantages will be understood from the foregoing which said polyhydric alcohol is selected from the group description, and it will be apparent that various changes consisting of a glycol, glycerine, a polyhydroxy alkane may be made without departing from the spirit and scope having 4 to 6 carbon atoms, a polyhydric phenol and a of the invention or sacrificing all of its material advanpolyphenol. tages, the form hereinbefore described being merely a 4. The adhesive of claim- 3 in which the polyhydric preferred embodiment thereof. alcohol is a glycerine.

I claim: 5. The adhesive of claim 3 in which the polyhydric 1. A laminating adhesive consisting essentially of a alcohol is a polyphenol. preformed solid synthetic resin having a substantially 6. The laminating adhesive set forth in claim 1 whereuniform cross section and extensive surface area relain said synthetic resin is coated with said adhesion protive to said cross section, and from about 2.0 to 12.0 meter. milligrams of an adhesion promoter per square inch of said synthetic resin surface in contact with said surface, References cued the file of thls patent said synthetic resin being a linear polyamide having an UNITED ES P E S intrinsic viscosity of at least 0.4 and being selected from 2 607 709 Simpson et a1, Aug. 19, 1952 the group consisting of a polymer of pentamethylenedi- 2 37 715 on May 5 1953 ammonium sebacate, a polymer of hexamethylenediam- 2 705 223 R f et 1 29, 1955 monium adipate, a polymer of hexamethylenediammoni- 2,7 0 944 Greenlee 23 1956 um sebacate, a polymer of decamethylenediammonium adipate, a polymer of decamethylenediammonium seba- OTHER REFERENCES cate, a polymer of m-phenylenediammonium sebacate, a Charlton: Alloying With Epoxies, Modern Plastics,

polymer of -amino-caproic acid, a polymer of 7-aminovolume 32, No. 1, September 1954, page 157. 

1. A LAMINATING ADHESIVE CONSISTING ESSENTIALLY OF A PREFORMED SOLID SYNTHETIC RESIN HAVING A SUBSTANTIALLY UNIFORM CROSS SECTION AND EXTENSIVE SURFACE AREA RELASAID SYNTHETIC RESIN SURFACE IN CONTACT WITH SAID SURFACE, MILLIGRAMS OF AN ADHESION PROMOTER PER SQUARE INCH OF SAID SYNTHETIC RESIN BEING A LINEAR POLYAMIDE HAVING AN SAID SYNTHETIC RESIN BEING A LINEAR POLYAMIDE HAVING AN INTRINSIC VISCOSITY OF AT LEAST 0.4 AND BEING SELECTED FROM THE GROUP CONSISTING OF A POLYMER OF PENTAMETHYLENEDIAMMONIUM SEBACATE, A POLYMER OF HEXAMETHYLENEDIAMMONIUM ADIPATE, A POLYMER OF HEXAMETHYLENEDIAMMONIUM SEBACATE, A POLYMER OF DECAMETHYLENEDIAMMONIUM ADIPATE, A POLYMER OF DECAMETHYLENEDIAMMONIUM SEBACATE, A POLYMER OF M-PHENYLENEDIAMMONIUM SEBACATE, A POLYMER OF 6-AMINO-CARPROIC ACID, A POLYMER OF 7-AMINOHEPTANOIC ACID, A POLYMER OF 11-AMINO-UNDECANOIC, A POLYMER OF 12-AMINO-STEARIC ACID, AND INTERPOLYMERS THEREOF, SAID ADHESION PROMOTER BEING A RESINOUS EPOXY GLYCERYL POLYETHER HAVING TERMINAL EPOXY GLYCERYL RADICALS UNITED WITH THE DIVALENT RESIDUE OF A POLYHYDRIC ALCOHOL THROUGH ETHER OXYGEN ATOMS AND HAVING AN EPOXIDE EQUIVALENT OF ABOUT FROM 140 TO
 375. 